促进小鼠骨髓间充质干细胞增殖和成骨分化的血管内皮生长因子

摘要

BACKGROUND:Vascular endothelial growth factor (VEGF) is a crucial factor for regulating bone marrow mesenchymal stem cells in microenvironment, which can promote endothelial differentiation of bone marrow mesenchymal stem cells. But there is no report about VEGF effect on regulating the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. OBJECTIVE:To investigate the regulatory role of VEGF in the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. METHODS:The bone marrow mesenchymal stem cells were isolated and cultured from mouse long bones. cellCounting Kit-8 was used to test the proliferation of bone marrow mesenchymal stem cells cultured with different concentrations of recombinant VEGF proteins. The appropriate concentration of VEGF recombinant protein was selected to test their effects on the osteogenic differentiation of bone marrow mesenchymal stem cells. The mRNA and protein levels of Osterix, Runx2, alkaline phosphatase, osteocalcin and heme oxygenase-1 in bone marrow mesenchymal stem cells under induction of VEGF were detected by molecular biology methods. RESULTS AND CONCLUSION:(1) VEGF promoted the proliferation of bone marrow mesenchymal stem cells dose-dependently, and 100μg/L was the optimum concentration. (2) VEGF promoted the expression of Osterix, Runx2, alkaline phosphatase and osteocalcin in bone marrow mesenchymal stem cells under osteogenic induction. Similar results were obtained by alizarin red staining and quantification of numbers of calcium nodules. (3) VEGF induced the expression of heme oxygenase-1 in bone marrow mesenchymal stem cells at mRNA and protein levels. These findings indicate that VEGF can induce the expression of heme oxygenase-1 i in bone marrow mesenchymal stem cells, and promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.%背景：血管内皮生长因子是骨髓间充质干细胞所处骨髓微环境中的重要调控因子，其可促进骨髓间充质干细胞的血管内皮方向分化，但尚无其对骨髓间充质干细胞增殖和成骨分化调控作用的报道。　　目的：探讨血管内皮生长因子对骨髓间充质干细胞增殖和成骨分化的调控作用及其机制。　　方法：分离、培养小鼠骨髓间充质干细胞，CCK8方法检测不同质量浓度血管内皮生长因子重组蛋白对骨髓间充质干细胞增殖的影响，选定适宜血管内皮生长因子重组蛋白质量浓度并检测其对骨髓间充质干细胞成骨分化的影响，分子生物学方法检测血管内皮生长因子干预下骨髓间充质干细胞中Osterix，Runx2，碱性磷酸酶、骨钙素和血红素氧化酶1的表达。　　结果与结论：①血管内皮生长因子可以促进骨髓间充质干细胞增殖，且具有浓度依赖性，100μg/L血管内皮生长因子重组蛋白的促增殖作用最显著。②成骨诱导剂存在条件下，血管内皮生长因子促进骨髓间充质干细胞成骨标志基因Osterix、Runx2、碱性磷酸酶和骨钙素的表达；血管内皮生长因子干预组骨髓间充质干细胞成骨分化的钙结节数量较对照组增加。③血管内皮生长因子可诱导骨髓间充质干细胞中血红素氧化酶1 mRNA和蛋白水平的高表达。以上结果表明血管内皮生长因子促进骨髓间充质干细胞增殖和向成骨细胞分化的调控机制可能与骨髓间充质干细胞内血红素氧化酶1表达增加有关。